A protective covering called
the myelin sheath
surrounds all the dendrites and the axon. The myelin sheath is a fatty layer that acts as a layer of insulation. This layer prevents the nerve signals of one neuron from interfering with that of another neuron.
Which part of the neuron is protected by a fatty layer?
Myelin sheaths
are sleeves of fatty tissue that protect your nerve cells. These cells are part of your central nervous system, which carries messages back and forth between your brain and the rest of your body.
What is the fatty insulation on the neuron called?
Much like the insulation around the wires in electrical systems, glial cells form a membraneous sheath surrounding axons called
myelin
, thereby insulating the axon. This myelination, as it is called, can greatly increase the speed of signals transmitted between neurons (known as action potentials).
What covers the myelin sheath?
The myelin sheath is a protective covering that surrounds
fibers called axons
, which are the long thin projections that extend from the main body of a nerve cell or neuron. This sheath is composed of protein and lipids.
Where are the oligodendrocytes found?
Oligodendrocyte, a type of neuroglia found in
the central nervous system of invertebrates and vertebrates
that functions to produce myelin, an insulating sheath on the axons of nerve fibres.
What is nervous tissue with diagram?
Nervous tissue is found in the brain, spinal cord, and nerves. It is responsible for coordinating and controlling many body activities. … The cells in nervous tissue that generate and conduct impulses are called neurons or nerve cells. These cells have three principal parts: the dendrites, the cell body, and one axon.
What are the 3 types of nervous tissue?
Neurons, or nerves, transmit electrical impulses, while neuroglia do not; neuroglia have many other functions including supporting and protecting neurons.
Which structure is covered by a fatty layer of insulation quizlet?
Many axons are insulated by surrounding layer of fatty material called
myelin sheath
.
Who controls reflex?
The spinal cord
is the primary control centre for reflex behaviour. The spinal cord connects the brain and the spinal nerves. So we can say that, reflex arc is controlled by the spinal cord.
What is the most common type of neuron?
Interneurons
.
Interneurons
are neural intermediaries found in your brain and spinal cord. They’re the most common type of neuron. They pass signals from sensory neurons and other interneurons to motor neurons and other interneurons.
What disease destroys the myelin sheath?
The most common type of demyelinating disease is MS. It happens when the immune system mistakenly attacks and damages myelin. The term
multiple sclerosis
means “many scars.” Damage to myelin in the brain and spinal cord can result in hardened scars that can appear at different times and in different places.
Which is not a function of the myelin sheath?
Humans cannot function without a myelin sheath because their neurons and nervous systems have evolved to
handle signals of a certain speed and quality
. Without these, the information cannot be processed in the same way by the nervous system, and the signals cannot be sent to muscles and organs.
What happens if you don’t have myelin sheath?
When the myelin sheath is damaged,
nerves do not conduct electrical impulses normally
. Sometimes the nerve fibers are also damaged. If the sheath is able to repair and regenerate itself, normal nerve function may return. However, if the sheath is severely damaged, the underlying nerve fiber can die.
Where is Neurilemma found?
Neurilemma (also known as neurolemma, sheath of Schwann, or Schwann’s sheath) is the outermost nucleated cytoplasmic layer of Schwann cells (also called neurilemmocytes) that
surrounds the axon of the neuron
. It forms the outermost layer of the nerve fiber in the peripheral nervous system.
How many axons can one oligodendrocyte Myelinate?
Oligodendrocytes do this by creating the myelin sheath. A single oligodendrocyte can extend its processes to
50 axons
, wrapping approximately 1 μm of myelin sheath around each axon; Schwann cells, on the other hand, can wrap around only one axon.
Are oligodendrocytes found in gray matter?
‘ Like other glia, oligodendrocytes are found
throughout the CNS gray and white matter
, where individual oligodendrocytes can myelinate as many as 40–50 axons. This important function enables rapid saltatory conduction throughout the CNS.
